Brake pedal module

This application claims priority to German Priority Application No. 102023104262.9, filed Feb. 21, 2023, the disclosure of which is incorporated herein by reference in its entirety.

The disclosure relates to a brake pedal module for a “brake-by-wire” brake system of a vehicle.

In the case of “brake-by-wire” brake systems, a braking request from a driver and/or driver assistance system is detected electronically, and the brakes of the vehicle are actuated by one or more purely electric actuators. For this purpose, provision can be made for each of the brakes of the individual wheels to be assigned an electric-motor actuator of the kind known, for example, in an “EMB” (electric-motor brake). However, it is also possible to provide for an electrohydraulic actuator to be controlled centrally in order to actuate the brakes hydraulically in a conventional manner, is known, for example, in an “IBS” (integrated brake system). Moreover, a “brake-by-wire” brake system can be embodied as a hybrid system in which the brakes on one vehicle axle, e.g. those at the front wheels, are assigned to an “IBS” and the brakes on another vehicle axle, e.g. those at the rear wheels, are each configured as an “EMB”.

Since there is generally no mechanical connection between a brake pedal and the brakes in “brake-by-wire” brake systems, a feedback behaviour of the brake pedal is simulated for the driver, e.g. by a counterforce unit. To be more precise, a higher resistance is effective as the brake pedal is actuated with an increasing travel.

Although such systems allow good simulation of a feedback behaviour of the brake pedal, integration into a vehicle environment is difficult on account of their size.

What is needed is to provide a brake pedal module which is particularly compact.

According to the disclosure, a brake pedal module for a brake-by-wire brake system of a vehicle is disclosed, having a brake pedal, which can be secured pivotably on the vehicle and can be moved between a rest position and an end position, and a feedback unit for producing a resistance during actuation of the brake pedal. The feedback unit has a first counterforce unit, which urges the brake pedal into the rest position, and at least one further counterforce unit, which acts in parallel with the first counterforce unit as regards their interconnection, and/or a damping unit, which acts in parallel with the first counterforce unit as regards their interconnection.

Since the first counterforce unit and the further counterforce unit and/or damping unit are arranged in parallel with one another as regards their interconnection, the feedback unit can have a short length without impairing the feedback behaviour of the brake pedal. Thus, according to the disclosure, the feedback unit can also be accommodated in restricted installation spaces.

The damping unit and the further counterforce unit can be in the form of a combined unit.

For example, a counterforce unit produces a resistance when the brake pedal is actuated. Moreover, the counterforce unit brings about a return of the brake pedal into its rest position after actuation of the brake pedal.

When the brake pedal is actuated, the damping unit produces speed-dependent damping and hysteresis, thereby producing a pedal feel familiar to the driver.

The brake pedal is an upright brake pedal, for example. In this case, the advantages of the shortened feedback unit are effective since, in the case of an upright brake pedal, there is generally only a relatively limited installation space for the accommodation of the feedback unit.

In one exemplary arrangement, the brake pedal module has a support component for securing the brake pedal module on the vehicle, wherein the brake pedal is mounted pivotably on the support component. This simplifies the assembly of the brake pedal since the brake pedal can be preassembled outside the vehicle.

The feedback unit can be arranged between the brake pedal and the support component. In this case, the feedback unit can be attached to the support component. An advantage is thereby achieved that the brake pedal module can be placed particularly easily in an installation space environment. The components are retained on one another in such a way that, apart from the modular unit being secured on the vehicle, no additional mechanical support of some of these components on the vehicle is necessary. For example, only the support component has to be secured on the vehicle.

Thus, all the components of the brake pedal module are mounted on the support component, ensuring that the brake pedal module is a preassembled modular unit which is self-contained in terms of the forces involved. Moreover, the brake pedal module can be a compact design.

According to one exemplary arrangement, the first counterforce unit and the further counterforce unit and/or the damping unit are modular units arranged separately from one another. This means that each of the modular units has its own housing. As a result, flexible positioning of the modular units is possible.

The first counterforce unit, on the one hand, and the further counterforce unit and/or damping unit, on the other hand, are, for example, each coupled at one end to the brake pedal and, at the other end, are mounted, for example, pivotably mounted, on the vehicle. Actuation of the brake pedal thus acts directly on the first counterforce unit and/or the further counterforce unit and/or damping unit, thus directly simulating a feedback behaviour when the brake pedal is actuated. By virtue of the mounting on the vehicle, stable support of the first counterforce unit and the further counterforce unit and/or damping unit is furthermore ensured.

According to an alternative exemplary arrangement, the first counterforce unit and the further counterforce unit and/or damping unit can be supported by the brake pedal, on the one hand, and on the vehicle, on the other hand, via a common pivot bearing. Since there is only one pivot bearing at the brake pedal, the complexity of the brake pedal module is reduced, and this has a positive effect on production costs. More specifically, the first counterforce unit and the further counterforce unit and/or damping unit can each be accommodated in a separate housing and coupled mechanically by a transmission link. That is to say that each unit is mounted on the vehicle via a dedicated pivot bearing.

In another exemplary arrangement, the feedback unit comprises a housing in which the first counterforce unit, on the one hand, and the further counterforce unit and/or damping unit, on the other hand, are arranged parallel to one another. Since a common housing is used to accommodate the first counterforce unit and the further counterforce unit and/or damping unit, assembly of the feedback unit is significantly simplified. To be more precise, the first counterforce unit and the further counterforce unit and/or damping unit do not have to be handled and installed as separate units. Moreover, just one single bearing is required for mounting the feedback unit on the vehicle, instead of two bearings when the first counterforce unit and the further counterforce unit and/or damping unit are arranged separately.

It is possible to secure the housing on the vehicle. For example, the housing is pivotably mounted on the support component. As a result, the feedback device is correspondingly pivoted during a movement of the brake pedal, thus ensuring that the feedback unit does not block the movement of the brake pedal.

It is possible for either the first counterforce unit, on the one hand, or the further counterforce unit and/or damping unit, on the other hand, to be fixed mechanically in a pivotable manner on the brake pedal. This means that only one of the two units is fixed mechanically on the brake pedal. This likewise contributes to simplified mounting of the brake pedal module.

That unit from the group comprising, on the one hand, the first counterforce unit and, on the other hand, the further counterforce unit and/or damping unit which is not fixed mechanically in a pivotable manner on the brake pedal can be supported in a sliding manner on the brake pedal. That is to say that the unit which is not mechanically coupled is supported in a sliding manner. On the one hand, overdetermination of the bearing arrangement is thereby avoided. A sliding bearing arrangement can furthermore be implemented in a particularly simple manner.

In an alternative exemplary arrangement, the first counterforce unit and the further counterforce unit and/or damping unit can be connected to one another by a transmission link. When actuated, the brake pedal acts on only one of the two units, but the further unit is likewise activated via the transmission link. This likewise contributes to simplified construction of the brake pedal module.

The housing can be aligned in such a way that the first counterforce unit and the further counterforce unit and/or damping unit are arranged one above the other or side-by-side or laterally offset with respect to one another in an installed state in a vehicle. In this way, a high flexibility is achieved in respect of the installation position of the feedback unit. In other words, the alignment of the feedback unit can be adapted to a prevailing installation space situation.

According to one exemplary arrangement, the brake pedal module comprises a sensing unit for detecting a braking request from a driver. For example, a braking request is detected electronically. Based on the detected braking request, a signal can be passed to the actuators assigned to the wheels, which then produce a braking effect.

The sensor unit comprises, for example, a sensor for detecting an actuating travel and/or an actuating angle, and/or a sensor for detecting an actuating force.

The brake pedal module according to the disclosure is suitable for use in a “brake-by-wire” brake system, which is preferably equipped with “EMB” brakes and/or is configured as an “IBS” system.

shows schematically a brake pedal modulefor a “brake-by-wire” brake system of a vehicle.

The brake pedal moduleis used, for example, to electronically detect a braking request from a driver.

The brake pedal modulecomprises a brake pedal, which can be secured pivotably on the vehicle.

The brake pedalcan be moved, for example pivoted, between a rest position and an end position. For this purpose, a driver can actuate the brake pedalwith their foot. In the figures, the brake pedalis illustrated in its rest position.

Furthermore, the brake pedal module comprises a feedback unit, which produces a resistance when the brake pedalis actuated.

Moreover, the brake pedal modulehas a support componentfor securing the brake pedal moduleon the vehicle.

The brake pedalis mounted pivotably on the support component.

However, it is also conceivable for there to be no support componentand for the brake pedalto be mounted pivotably directly on a vehicle floor in the mounted state in the vehicle.

The feedback unitis arranged between the brake pedaland the support component. In the exemplary arrangement, the feedback unitis attached to the support component.

The brake pedaland the feedback unitare thus pre-mounted on the support component. This means that, when the brake pedal moduleis installed in an installation space environment, only the support componenthas to be secured on the vehicle.

The brake pedalis formed by a strut.

At a free end, the struthas an actuating surface, which can be pressed by the foot of a driver to indicate a braking request.

The brake pedal modulefurthermore comprises a sensor unitfor detecting a braking request from the driver. In the exemplary arrangement, the sensor unitcomprises an angle sensor, which is arranged on a pivot bearing of the brake pedal. However, it is also conceivable that the sensor unitalternatively or additionally comprises a force sensor.

The feedback unithas a first counterforce unit, which urges the brake pedalinto the rest position.

Furthermore, the feedback unithas a unitwhich acts in parallel with the first counterforce unitas regards their interconnection and, in the exemplary arrangement shown in, is a combined counterforce unit and damping unit. However, the further unitcan also be designed exclusively for damping or as a counterforce unit without a damping action.

In the exemplary arrangement shown in, the first counterforce unitand the counterforce and damping unitare modular units arranged separately from one another, which, in particular, are each accommodated in a dedicated housing,.

The first counterforce unit, on the one hand, and the combined counterforce unit and damping unit, on the other hand, are each coupled at one end to the brake pedaland, at the other end, are mounted, for example pivotably mounted, on the vehicle. More specifically, the two housings,are each mounted pivotably at one end on the support component.

The first counterforce unitcomprises a pistonand a return spring, which urges the pistoninto an unactuated initial position. The piston is in the unactuated initial position when the brake pedalis not actuated. The unactuated initial position corresponds to a position of the brake pedalin the rest position.

When the brake pedalis actuated, the return springproduces a resistance, which contributes to producing the feedback behaviour of the brake pedal. Moreover, the return springserves to move the brake pedalback into its rest position.

In one exemplary arrangement, the return springis designed as a progressively acting spring arrangement. A spring arrangement of this kind comprises at least one spring element and has a non-linear characteristic. To be more precise, a progressive spring arrangement is relatively soft when the effective force is low, and becomes harder as the load increases.

The combined counterforce and damping unitlikewise has a piston, which delimits the pressure chamberin the housing. When the brake pedalis actuated, the pressure chamberis compressed by the displacement of the piston.

Furthermore, the pistondelimits a vacuum chamberin the housing, the volume of which is enlarged when the brake pedalis actuated.

To seal off the pressure chamberand the vacuum chamberfrom one another, a ring seal, which rests against an inner wall of the housing, is arranged on the piston.